‘Fire tornado’: Video captures jaw-dropping phenomenon at B.C. wildfire

globalnews.ca:

wildfires burning throughout the province’s interior.The phenomenon was captured Thursday night by overnight ground personnel working the Downton Lake fire, burning in the Gun Lake area north of Pemberton.In the video, a towering column of gas and flame can be seen spinning along the lakeshore, in front of a hellish backdrop of flaming trees.In a social media thread, the BC Wildfire Service explained that the “fire whirl,” also known as a fire tornado, was the product of unique and rapidly changing weather conditions.At the time the fire whirl formed, the region was coming out of a multi-day heat wave, followed by a strong cold front.As the front swept through the area, it brought strong southwesterly winds which engorged the fire.The relative humidity in the area fell to an “incredibly rare” overnight low of 14 per cent, while the dew point — a measure of moisture in the air — fell precipitously from the day before, the wildfire service explained.“With this combination of conditions and fire behaviour, fire intensity was more extreme during this overnight period, reaching intensities that hadn’t been seen even during the day,” the service explained.“As shown in the video, the combination of high fire intensity, strong winds and air mass instability resulted in the formation of a fire whirl (otherwise known as a fire tornado) over Gun Lake.”The formation of the whirl was also aided by the presence of “adequate vorticity,” the tendency of the atmosphere to spin or rotate, the wildfire service explained.“Complex terrain, downslope winds and the passing cold front provided the necessary conditions for the formation of this fire whirl over Gun Lake,” it said.The fire service added that such fire tornadoes are “incredibly